/usr/share/doc/qtdeclarative5-qtquick2-plugin/changelog.Debian.gz is in qtdeclarative5-qtquick2-plugin 5.2.1-3ubuntu15.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/qtdeclarative5-qtquick2-plugin/../libqt5qml5/changelog.Debian.gz